This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To get diffraction data for SAD phasing to solve the crystal structure of ADAT2/3 (adenosine deaminase that acts on tRNA) complex. The 3-D structure of ekaryotic ADAT has not been known yet, although there are several bacterial homologues. Eukaryotic enzymes are significantly different from bacterial ones in size, substrate specificity and etc. This would be a novel structure of the enzyme which is also realated to other important enzymes that acts on RNA or DNA in cells including activation induced cytidine deaminase (AID)or APOBEC enzymes.